1. Field of the Invention
The present invention relates to valve locking devices. More specifically, the present invention pertains to a device for preventing movement of the operating handle of a fluid valve.
2. Description of the Prior Art
There are various reasons for preventing the opening or closing of a fluid valve. Utility companies may lock a water or gas valve closed to terminate service of a delinquent customer or to prevent flow of water and/or gas into a vacant house. More importantly, fluid valves are frequently locked open or closed in certain industrial operations for safety purposes. For example it may be extremely hazardous to interrupt fluid flow through a valve in a chemical process or in a valve supplying energy to machinery or equipment. In many cases, particularly during maintenance procedures, it may also be important to lock a fluid valve closed to prevent operation of a process, equipment or machinery during such maintenance operations. There are many other reasons for locking a valve opened or closed.
A number of devices have been developed for locking a valve in a certain position. A few examples are shown in U.S. Pat. Nos. 4,872,327; 5,806,555 and 6,164,318. These devices vary in complexity and operations, depending upon the specific use for which they were designed.
It is of course most important that valve locking devices be effective and tamper proof. It would also be desirable if they were easy to use, inexpensive and trouble free. The search continues for effective locking devices which prevent movement of the operating handle of the fluid valve which is effective, tamper proof and easily used. The present invention seeks to provide these characteristics.
The present invention comprises a locking device for preventing movement of the operating handle of a fluid valve. The device includes a U-shaped rod member having a curved proximal portion from which extends parallel portions terminating in a pair of spaced apart distal ends. The rod member is insertable through some portion of the valve so that the proximal portion thereof is substantially interengageable therewith, the distal ends of the rod member extending on opposite sides of the valve handle to prevent movement thereof.
The device also includes first and second elongated arm members corresponding proximal ends of which are pivotally connected. Each of the elongated arm members is positionable on opposite sides of the U-shaped rod member so that when distal ends of the arm member are brought together the U-shaped member is confined thereby to prevent movement of the valve handle. The parallel portions of the arm members are provided with cooperating apertures which, when the distal ends of the arm members are brought together, are aligned for engagement with the shackle of a padlock for securing the arm members to the U-shaped rod member in their confined relationship therewith.
In preferred embodiments, each of the parallel portions of the rod member are provided with uniformly spaced corresponding holes whose axes are perpendicular to the axes of the parallel portions of the rod member. At least one of the arm members is provided with a pin member which is engageable with a selected one of the uniformly spaced holes of the rod member when the distal ends of the arm members are brought together, to prevent movement of the rod member from its enclosed relationship with the arm members. The other of the arm members may be penetrated by a corresponding pin hole. The pin member of one arm member is then extendable through a select one of the uniformly spaced rod member holes into the pin hole, providing additional tamper proof characteristics.